Systems and Methods for Remote Testing of a Flow Switch

ABSTRACT

Systems and methods for the remote testing of a paddle-type flow detector, such as are common in fire protection systems. Specifically, the systems and methods provide for mechanical movement of the vane to test activation of the flow detector under a flow condition, and which measure the amount of time the vane takes to return to the ready position to verify the presence of a paddle on the vane.

BACKGROUND

1. Field of the Invention

The present invention generally relates to switches and switch testingapparatus. Specifically it relates to switches that are triggered byfluid flow and remote testing thereof.

2. Description of the Related Art

To fight fires in modern buildings, firefighters use a wide variety oftools but are also regularly aided by systems within the building.Modern buildings almost universally include water-based fire protectionsystems to control or extinguish fires. Fire sprinkler systems generallyfollow a fairly standardized principle. A liquid firefighting material(generally water) is maintained in a series of pipes, generally underpressure, which are arranged throughout all areas of the building.

In a wet pipe system, water is actually stored within the pipes, whereasin a dry pipe system, water is stored external to the building while thepipes contained pressurized air, nitrogen, or other gas. Attached tothese pipes are various sprinklers which, when activated, will spray theliquid into a predetermined area. When a fire situation is detected,sprinklers on the pipe structure are activated by heat. This opens themand allows them to spray water from the pipe system.

The heat activation is generally performed by a heat sensitive element,an integral part of the sprinkler, which is activated by the heat fromthe fire. Specifically, the sprinkler utilizes a “plug” holding itclosed. The plug is damaged by heat which results in the pressurizedwater inside the pipes being pulled to and through the opening in thenow activated sprinkler head. Generally, each sprinkler has its own heatsensitive element and is activated independent of all other sprinklers.This action dispenses the liquid on the fire and serves to control orextinguish the fire.

This system can be very effective because there is no reliance onnotification systems or other separate components where a communicationbreakdown could occur. There is always concern in a fire protectionsystem, that the fire could damage any form of notification system priorto it being able to provide notice. In the plug arrangement discussedabove, there is very little possibility of the sprinkler system failingto activate due to damage from the fire. As the damage causes theactivation, the system simply enters into a spray mode at thatsprinkler. Further, the sprinkler will generally spray until the systemis shut off as the water source is often municipal water lines providinga steady feed and there is no switch which can serve to replug thesprinkler once activated. Instead, the unit must be replaced.

Because of the fact that most fire protection systems utilize these typeof heat activated sprinklers, they generally do not use smoke detectorsor other forms of fire detection apparatus to activate the system. Whilethis works from a fire fighting perspective, in a large building it isoften necessary to notify both occupants of the building that the systemhas activated, and to notify the fire department that the system hasactivated so that they can come and fight the fire. Therefore, systemsbeyond those simply to activate the fire sprinkler are desirable as partof the system.

While some sprinkler systems utilize smoke detectors and other detectionmechanisms to provide notification, others do not. Further, even if theyinclude detection apparatus, it can be desirable to know if only smokehas been detected and/or if a sprinkler head has activated. Further,detection and notification systems can be damaged by the very fire thatthe sprinkler has reacted to prior to providing notification. Therefore,most sprinkler systems utilize a system to detect that a sprinkler headhas activated as an alternative notification system.

While these detection systems can be simple or complex, most rely uponfluid flow within the pipes of the sprinkler system to detect that asprinkler head has activated. In particular, when a sprinkler head (ormultiple heads) activate, fluid in the pipes will go from a staticcondition, to a condition where the fluid is moving toward the activatedhead. This fluidic movement can be detected through the use of a flowdetector which is placed in the fluid stream and when the flow detectordetects fluid motion (“flow”), an alarm condition is activated toprovide notification that water is being dispensed by the system.

Because fluid flow specifically indicates a sprinkler head activation,or a system failure resulting in water dispensing which is anotherpotential emergency, the flow detector is an excellent form ofnotification of potential danger. Based on the output of a flow detectoralong with output of other detectors, information can also be gatheredas to the potential location of a fire, or if there may be a damagedpipe which is generating flow in a non-fire situation. In a large officebuilding, the ability to send emergency personnel to the correctlocation quickly can often decrease property damage and potentially savelives.

Flow detectors are more commonly used in wet-pipe systems and most areof relatively straight forward design. They generally comprise anelongated vane including a paddle which extends generallyperpendicularly into a pipe in the system, often a large main pipe orriser so that movement of the fluid is detected wherever in the systemit occurs. However, flow detectors may be placed on particular pipecomponents to assist in localizing the position of the flow. The waterflow through the pipe forces the paddle forward, which then causes atrip switch at the other end to trip an internal switch activating thealarm condition.

The most common liquid used in fire protection systems is water becauseit is readily available, non-toxic, and quite effective in firefighting.Water, however, is an electrolyte which can enable electrochemicalcorrosion to occur where metal and oxygen are also present. Further, thewater used in sprinkler systems is generally not pure and can contain amultitude of dissolved solids, water treatment chemicals, andmicroorganisms. These impurities can contribute to corrosion, includingmicrobiologically induced corrosion, damaging pipes or other componentsthat make up the water-based fire protection system when the system isprepared and “armed” awaiting a possible fire situation. The presence oftrapped air (particularly the oxygen in the air) and how active a systemis (how often it is drained and filled) will also contributesignificantly to corrosion and its damaging effects in water-based fireprotection systems.

The degradation of components such as flow detectors is an unavoidableconsequence of the inclusion of water in the system. The presence ofwater within the piping can result in the failure of mechanicalcomponents to perform as intended when needed due to components becomingcorroded while they are held in their “ready” state. Flow detectors andother types of mechanisms in a fire protection system are particularlysusceptible to failure because they often sit for long periods of timein a ready state (switched off) and need to quickly adjust to a newstate (switched on) upon the fire system activating. Because of the riskof failure of components such as flow detectors, it is generally desiredto periodically test them to insure that they function.

While flow switches can be tested by flowing water through an inspectionport (which creates flow through the system simulating an activatedsprinkler), this system can be cumbersome. Therefore, it is oftendesirable to test flow switches remotely without need of flowing waterthrough the entire fire sprinkler system. One system to test flowswitches is described in U.S. Pat. No. 6,462,655. This system, whileeffective, is very complex in that it requires a localized fluid “loop”which is generated to create a limited area of fluid flow about the flowswitch within the otherwise static pipe system. While it is effective atperforming a flow test, and effectively tests that the flow switch willoperate under an actual flow condition, the system is complex toconstruct, includes additional components vulnerable to corrosion, andis relatively expensive.

SUMMARY

Described herein, among other things, are systems and methods for theremote testing of flow detectors in a fire sprinkler system.Specifically, they are directed to systems and method for the remotetesting of flow detectors.

Generally these systems and methods test a number of aspects of the flowdetectors during the course of a test run. In particular, there aregenerally three things that are tested for during the test run. First,the system tests that the flow detector is moveable in the forwarddirection (the direction of flow during a fire) and that movement of thevane to the desired trip position does, in fact, trip the alarm. Thesecond test is that the vane, once the alarm has tripped, returns backto its default “ready” position so that the test does not disable theflow detector. The third test is to validate that paddle is present andwill serve to move the vane when presented with a flow.

For at least the above reasons, described herein, among other things,are systems and methods for the remote testing of a paddle-type flowdetector, such as are common in fire protection systems. Specifically,the systems and methods provide for mechanical movement of the vaneassembly and specifically the trip stem to test activation of the flowdetector under a flow condition, and which measure the amount of timethe vane assembly takes to return to the ready position to verify thepresence of a paddle.

There are described herein, among other things, a self-test system for apaddle-type flow detector, the system comprising: an arm, the arm beingused to displace a trip stem from a first position to a second positionwherein said trip stem is biased to said first position and said flowdetector indicates flow when said trip stem is in said second position;a first sensor, the first sensor detecting when said trip stem is insaid first position; a second sensor, the second sensor detecting whensaid trip stem is in said second position; wherein, when said trip stemis in said second position, said arm releases said trip stem and saidtrip stem returns to said first position because of said biasing;wherein, said self-test system determines the amount of time betweenwhen said first sensor stops detecting said trip stem and said secondsensor detects said trip stem after said arm releases said trip stem;and wherein based on said amount of time, said self-test systemdetermines if a paddle is present on said trip stem.

In an embodiment of the system said arm rotates about an axis and may besized and shaped to release said trip stem suddenly. In an embodiment,it may be generally teardrop-shaped.

In an embodiment, the arm rotates about said axis a first direction whensaid arm is displacing said trip stem and a second direction after ithas released said trip stem. The system may further comprise a one-waygate, said one-way gate being attached to said trip stem such that saidone-way gate is rigid when said arm moving in said first directioncontacts said one-way gate, but opens when said one-way gate iscontacted by said arm moving in said second direction.

In another embodiment of the system it may comprise a one-way gateattached to said trip stem.

There is also described herein the system wherein said first sensor andsaid second sensor each comprise switches; wherein said first switch isclosed when said trip stem is in said first position; and wherein saidsecond switch is closed when said trip stem is in said second position.

There is also described herein a paddle-type flow detector including anauto-test system, the detector comprising: a housing; a vane assemblyextending from said housing; a biasing mechanism biasing said vaneassembly to a first position; a first sensor which detects when saidvane assembly is in said first position; a second sensor which detectswhen said vane assembly is in a second position; an arm within saidhousing, said arm displacing said vane assembly from a first position toa second position when an auto-test is initiated; wherein, when saidvane assembly is in said second position, said arm releases said vaneassembly and said vane assembly returns to said first position becauseof said biasing; wherein, said detector determines the amount of timebetween when said first sensor stops detecting said vane assembly andsaid second sensor detects said vane assembly after said arm releasessaid vane assembly; and wherein based on said amount of time, saiddetector determines if a paddle is present on said vane assembly.

In an embodiment of the detector the paddle-type flow detector isposition in a fire sprinkler system which may be a wet pipe system.

In an embodiment of the system said arm rotates about an axis and may besized and shaped to release said vane assembly suddenly. In anembodiment, the vane assembly comprises a trip stem which may have a oneway gate attached thereto.

In an embodiment, the arm rotates about said axis a first direction whensaid arm is displacing said vane assembly and a second direction afterit has released said vane assembly. The system may further comprise aone-way gate, said one-way gate being attached to said vane assemblysuch that said one-way gate is rigid when said arm moving in said firstdirection contacts said one-way gate, but opens when said one-way gateis contacted by said arm moving in said second direction.

There is also described herein the system wherein said first sensor andsaid second sensor each comprise switches; wherein said first switch isclosed when said vane assembly is in said first position; and whereinsaid second switch is closed when said vane assembly is in said secondposition.

In an embodiment the detector, comprises a key box, said key boxallowing a user to initiate the self-test which may include an indicatorindicating the result of said self-test.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the embodiments described herein and toshow more clearly how they may be carried into effect, reference willnow be made, by way of example only, to the accompanying drawings whichshow at least one example embodiment.

FIG. 1 is a perspective view of a flow detector of the prior art withthe housing removed to show internal components;

FIG. 2 is a perspective view of an embodiment of a flow detectorincluding a self-test system with the housing partially removed;

FIGS. 3A and 3B show a partial perspective and cut-away side viewrespectively of an embodiment of a flow detector in a pre-test or“ready” state.

FIGS. 4A and 4B show a partial perspective and cut-away side viewrespectively of an embodiment of a flow detector as the testing armcontacts the one-way gate.

FIGS. 5A and 5B show a partial perspective and cut-away side viewrespectively of an embodiment of a flow detector as the testing armdisplaces the trip stem and the alarm condition is triggered.

FIGS. 6A and 6B show a partial perspective and cut-away side viewrespectively of an embodiment of a flow detector after the testing armreleases the vane assembly and the vane has returned to its original orvertical state due to biasing of the vane assembly.

FIGS. 7A and 7B show a partial perspective and cut-away side viewrespectively of an embodiment of a flow detector as the arm is passingthrough the one-way gate moving the other direction after testing iscompleted.

FIG. 8 is a block diagram showing the controller and display inconjunction with the flow detector in place in a fire sprinkler system.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

This disclosure provides systems and methods for the testing of flowdetectors in situ in a fire protection sprinkler system. It should berecognized, however, that the test systems and methods discussed hereincan be used with flow detectors in other applications and not those usedjust in fire protection. Further, the systems and methods can be used totest other “motion” switches which rely upon a lever arm (such as a tripstem and paddle) to detect motion.

FIG. 1 provides for a general overview of a vane type flow detector (10)of the type known to those in the art. The flow detector (10) generallyincludes a couple of major components. Specifically, it includes thevane assembly (11) which comprises a trip stem (12) and an expandedpaddle (13) arranged toward its distal end (15). Toward the proximalend, the trip stem (12) is generally connected to a housing (17) aboutan axis of rotation. This axis allows the vane assembly (11) to rotatethrough a 2 dimensional arc generally perpendicular to the faces (33)and (35) of the paddle (13). The arc is generally constrained by thehousing (17) so that the vane assembly (11) cannot rotate a full 360degrees, but instead will rotate through a predefined arc.

In an embodiment, the arc is selected so that the vane assembly (11) canonly move one direction from the vertical position and the vane assembly(11) may included a biasing mechanism to insure that the natural restingstate is vertical. It should be recognized that “vertical,” as usedherein, does not require that the vane assembly (11) be perpendicular tothe ground when installed (it may in fact be horizontal). Instead, it isgenerally used to refer to the fact that the vane assembly (11) isperpendicular to the housing (17), which will then generally make itperpendicular to the length of the pipe into which it is placed, andthus perpendicular to the fluid flow. Throughout this disclosure, theterm “vertical” will be used to refer to this perpendicularity relativeto the housing, pipe, and/or fluid flow rather than any specificrelation to the earth's surface and is also used to refer to its “ready”state when the vane assembly (11) is generally within activation.

When the vane assembly (11) moves through the allowed arc, at theterminal position it will generally close a switch which is part of aswitch and retard assembly (19). The switch may be any type of switchbut generally standard electromechanical switches will be used wherebythe trip stem (12), when at the terminal point of the arc, serves toclose a connection. This closure can then be detected by electricalcomponents (such as a processor) in the detector (10) to serve as thealarm trigger. The retard component will generally implement a retardtime delay so that closing of the switch does not immediately trigger analarm. Generally, the vane assembly (11) will include some form ofbiasing member (such as a spring) to return it to the vertical positionabsent the imposition of any internal force so that when the flowdetector (10) is positioned in a static fluid, or in a relatively slowflowing fluid, the vane assembly (11) does close the switch. Insteadflow of a sufficient force must be present in the system. The retardtime delay further reduces false positives by requiring a consistentsignal for some time prior to alarm activation. This helps to reducefalse positive activations of the detectors (10).

In operation, the flow detector (10) will be placed into the pipe withthe paddle (13) extending into the fluid and the faces (33) and (35)directed across the intended flow. Should fluid begin to flow throughthe pipe, the force of movement will serve to push on the upstream face(33) of the paddle pushing the vane assembly (11) downstream. Becausethe rotation point of the vane assembly (11) is generally toward theproximal end, the force on the paddle (13) will allow the vane assembly(11) to act as a lever arm and will cause rotation of the vane assembly(11). As should be apparent, due to the length of the trip stem (12) andthe surface area of the face of the paddle (13), the flow can cause thevane assembly (11) to rapidly tilt through the available arc. Due to thebiasing, a very small flow will generally not serve to move the vaneassembly (11) far enough forward to trigger the switch (19), but afaster flow will cause the vane assembly (11) to trigger the switch(19). It should be recognized that switch (19) is generally locatedupstream of the vertical position of the vane assembly (11) because ofthe vane's (11) rotation about the axis. Further, a sufficient flowshould keep the switch (14) closed so long as the flow continues at orabove a predetermined level indicative of a sprinkler head beingactivated.

FIG. 2 shows a general perspective view of an embodiment of a flowdetector (100) which includes a self-test system. In order to protectthe self-test system (101), and inhibit dust or other materials fromgetting in the self-test (101) system, the self-test system (101) willgenerally be contained within the flow detector's (100) protectivehousing (117). In the depicted embodiment, the self-test system (101) isalso maintained within a secondary housing (103) to separate it fromother components that could interfere with its operation and furtherprotect it.

In order to test the flow detector (100), the self-test system (101)comprises a testing arm (201) which serves to push the trip stem (112)to the activated position. In the activated position a sensor (switch(205) in the depicted embodiment) detects the trip stem (112) andtriggers the alarm condition. The arm (201) is then designed to releasethe trip stem (112) to test that the vane assembly (111) returns to theready “vertical” state under the biasing. After this, the arm (201)returns to the pre-test position resetting the self-test system (101)and placing the detector (100) again in the ready state.

As part of the testing, the proximal end (125) of the trip stem (112),in the depicted embodiment, includes a one way gate (203). The gate(203) allows for the arm (201) to reverse direction and return to theready state with out pushing the vane assembly (111) in a directionopposing the expected flow. While in an alternative embodiment this isnot necessary and the arm (201) can simply continue rotating in the samedirection to return to the ready state, the reversing methodology ispreferred to save space and to better detect the position of the arm(201).

The structure in the depicted embodiment is best understood based on itsoperation and is shown in various positions in FIGS. 3-7. FIGS. 3A, 4A,5A, 6A, and 7A show a perspective view of the arm (201) and gate (203)operation while FIGS. 3B, 4B, 5B, 6B, and 7B show the flow detector(100) in the same positions from a side cutaway view that betterillustrates positioning of the vane assembly (111).

The testing arm (201), will serve to push against the proximal end (125)of the trip stem (112) so as to displace the paddle (113) downstream(although at the time of testing there is generally no fluid movementindependent of that caused by the testing so “downstream” is based onthe expected fluid movement that would result in the flow detector (100)activating). In the depicted embodiment, the testing arm (201) comprisesa generally smooth-sided generally tear drop-shaped finger capable ofrotating about an off-centered axis (241). Specifically, the arm (201)includes a back rotational section (211) which is generally rounded anda generally triangular section (213). The triangular section includes asmooth front edge (215) and a contrary back edge (217). The two edges(215) and (217) terminate at a point (219).

While this specific structure is not required in alternative embodimentsand the arc can be triangular, spiral, or any other shape depending onembodiment, this structure provides for a very effective means ofdisplacing the proximal end of the trip stem (112) to perform the firstpart of the testing as discussed below, while also getting the arm (201)out of the way to perform the second and third parts of the testing.Rotation of the arm (201) will generally be induced by a motor (207) orother mechanism to provide rotary motion about the axis (241) oncommand.

In the depicted embodiment, the arm (201) initially rotates in aclockwise direction (as viewed in the Figures) from the pre test point(position where testing is not occurring and when the flow detector(100) is in standard operation) shown in the various FIGS. 3A and 3B, toa completed point as shown in FIGS. 6A and 6B. The arm (201) thenreturns to the pre test position by rotating back to the position ofFIGS. 3A and 3B through the arrangement of FIGS. 7A and 7B.

In operation, testing occurs as follows for the depicted embodiment.Upon initiation of the test, the arm (201) will move from the pre-testposition of FIGS. 3A and 3B and rotate upstream (clockwise in thedepiction) until it hits the one way gate (203) which is located at theproximal end (125) of the trip stem (112). Contact with the gate (203)is shown in FIGS. 4A and 4B. The gate (203) will be designed to swingabout its axis (233) in the depicted embodiment with its free end (231)moving from left to right of FIGS. 3-7. Thus, when the arm (201) hitsthe gate (203) in FIGS. 4A and 4B moving in the clockwise direction itcontacts an essentially rigid object which cannot rotate in thatdirection.

Since the gate (203), when contacted in this direction, is effectivelyrigidly attached to the trip stem (112) of the vane assembly (111), theproximal end (125) will be pushed away from the arm (201) as shown inFIGS. 5A and 5B. The gate will first contact the front edge (215) andthen the point (219) resulting in the vane assembly (111) moving throughthe same arc it would if there was a detectable flow as can be seen inFIG. 5B. Upon the vane assembly (111) reaching its terminal location,the point (219) will generally be touching the upper periphery of thegate (203) (as shown in FIG. 5A) and the trip stem (112) will bepositioned to close the switch (205) which activates the alarm if allcomponents are working properly.

The arm (201) will generally not cease its rotational motion upon theswitch (205), being tripped (successfully or not) but will continue torotate clockwise (possibly after a brief hold) from FIGS. 5A and 5Bwhich will allow the tip (219) of the arm (201) to completely clear thegate (203). When this happens, there is now no longer any force beingapplied to the gate (203) or the vane assembly (111) excepting thebiasing force initially present. Thus, the vane assembly (111) will bebiased back to its original vertical position. Due to the shape of thearm (201), the arm (201) is generally completely clear of the gate (203)as soon as the point (219) passes over the edge of the gate (203) andthe return of the gate (203) passes below the back edge (217) whichallows the vane assembly (111) to “snap” back to the vertical positionunder the force of the biasing.

Assuming the flow detector (100) is functioning correctly, the vaneassembly (111) being allowed to return will disengage the switch (205)as soon as the tip (219) clears the gate (203) deactivating the alarmcondition and indicating that the biasing mechanism is functioning. Asshould be clear, in the event a retard time delay was provided, the arm(201) can be sized or shaped to provide that the trip stem (112)contacts the switch (119) for sufficient time to trigger the alarmcondition before being allowed to snap back. It should also be notedthat in an alternative embodiment the amount of force to move the vaneassembly (111) from the position of FIG. 4A to the position of FIG. 5Acan also be measured to test if the correct amount of biasing force ispresent.

Once the test run is completed, the arm (201) will need to return to itspre-test position. In the depicted embodiment, the arm (201) in FIG. 6will at this time reverse rotation (rotating counter-clockwise in theFIGS. 3-7) and will again contact the one way gate (203). However, whenrotating in this direction, the gate (203) opens and is pushed out ofthe way by the arm (201) so that the vane assembly (111) does not move.The arm (201) passing back through the gate (203) is shown in FIGS. 7Aand 7B. As the arm (201) continues to rotate counterclockwise it willagain clear contact with the one way gate (203) from the tip (219)rising to sufficient height. The gate (203) will generally be biased tothe closed position of FIGS. 3-6 and thus the auto-test system (101)will return to the arrangement of FIGS. 3A and 3B where it is againready to be used.

As discussed above, in an alternative embodiment, the one way gate (203)can be eliminated (replaced with a rigid point of contact) as the arm(201) can rotate through the remaining portion of a full 360 degrees toclear from the position of FIG. 6 to arrive at the position of FIG. 3instead of reversing its direction. However, while this is acceptable,it is generally a less preferred mechanism as it requires the housing(117) and (103), to have space to accommodate the arm (201) rotatingthrough the upper vertical position (which extends it beyond its motor),which can be undesirable.

While the above description has provided for two tests to make sure theflow detector (100) is operating properly, one of ordinary skill wouldrecognize that the tests above only test operation of the trip stem.They do not actually test operation of the other portion of the vaneassembly (111). Specifically, movement of the trip stem (112) does nottest if the paddle (113) interacts with a flow. That is, if the paddle(113) has broken or come loose from the vane assembly (111), the abovetesting would still indicate correct function so long as the trip stem's(112) proximal end (125) was still present.

In order to test that the paddle (113) is still present, is within thefluid, and would be expected to push the vane assembly (111) should afluid flow commence, the flow detector (100) generally performs a thirdtest in addition to the above two. Specifically, the flow detector (100)includes a second sensor (in this embodiment switch (255)) which detectsthe vane assembly (111) when it is in the vertical position. Thus, thevane assembly (111) effectively has three positions. A first position(FIG. 3) where the vane assembly (111) has closed switch (255), a secondintermediate position where the vane assembly (111) is moving throughthe arc and is between the two switches (255) and (205), and a thirdposition (FIG. 5) where the vane assembly (111) is closing switch (205).

When the vane assembly (111) moves from the position shown in FIG. 5 tothat of FIG. 6, the paddle (113) sweeps through the fluid in the pipewhose flow the flow detector is monitoring. Because the paddle (113) isdesigned to be pushed by the flow, this movement will result in thefluid being displaced by the moving paddle (113). This displacement willresult in force being applied to the paddle (113) and can be used todetect that the paddle (113) is still present and is undamaged.

Specifically, the force applied to the paddle (113) due to the fluidbeing displaced will increase the amount of time it takes for the paddle(113) to return to the vertical. The time of displacement can bedetected based on the time between when the switch (205) is opened (thevane assembly (111) leaves the flow position of FIG. 5) and when theswitch (255) is closed (the vane assembly (111) returns to the readyposition of FIG. 6) under the force from the biasing. If this time isgreater than an expected window, where the time of “additional delay” isbased upon the size of the paddle (113), the paddle (113) is presumed tobe present and passing through fluid and the paddle's (113) presence andoperation is verified. If the time to return is below this range, thereis a potential error condition which can result in additional testing oran indication that the paddle (113) should be replaced.

It should be recognized that the specific amount of time that is used asa cutoff for when the paddle (113) is expected to be present vs. notpresent is dependent on a number of factors. Specifically, the type andamount of fluid present in the system, the size and shape of the paddle(113), and the biasing force of the biasing system. It will beunderstood by one of ordinary skill that the trip stem (112) will takesome time to move between the two positions regardless of the presenceor absence of the paddle (113) and a damaged paddle (113) may result ina time which is between the above two. Generally, therefore, thethreshold time indication that a paddle (113) is present will be abovethe time it takes for trip stem (112) alone to return (the paddle (113)is totally missing). It may also or alternatively be set below a valuefor the paddle (113) to return on average when it is undamaged. In thisway, a paddle (113) with sufficient damage to potentially present afailure circumstance can be detected, but a lesser damaged paddle (thatwill still work) will read as still present and acceptable.

Timing and determination of whether the paddle (113) is present willgenerally performed by a processor onboard the flow detector (100), butthat is by no means required and it can be performed by externalmechanics or electronics. In an alternative embodiment, the flow testingcan determine if the paddle is present by detecting the amount of forcerequired to move the vane through the arc from FIG. 4 to FIG. 5. In astill further embodiment, both tests can be performed together.

The depicted self-test system (101) provides for testing as to thefunctionality of the flow detector (100) onboard the flow detector(100). That is, the self-test system (101) is preferably located“on-board” the flow detector (100). In this way, the self-test system(101) generally provides for testing in situ without need to alter oraccess components of the fire sprinkler system (1). As shown in FIG. 8,the self-test can be initiated remotely from the flow detector (100)which is in place in a pipe (821) filed with water (823) through the useof a wired or wireless connection (801). Remote control is generallypreferred. A user can operate a controller (803) to initiate the test.This controller (803) can be of any type known to those of ordinaryskill, but will generally be a “key box” or similar structure where akey (805) or other locking mechanism inhibits the testing from being runby those other than authorized personnel.

In an embodiment of a key box controller (803) operating the self-testsystem (101), a key (805) is inserted into a corresponding slit (807)and turned to either activate a series of buttons or switches (809)which are used to initiate the testing, or the turning of the key (805)activates the test itself. In an embodiment, the self-test system (101)can perform the entire test process in an automated fashion onceinitiated (that is, once commenced the testing is performed in itsentirety without further human intervention) or the user can moredirectly initiate individual portions of the test upon specific commandor indication.

In order to provide notification to the user of the result of the test,an indicator (811) (such as an LED light bank, a display, and/or anaudible speaker) can provide feedback to the user of what occurredduring the test. This output may be a simple pass or fail indication, ormay provide for additional feedback such as by indicating specificpassage or failure of different parts of the test, or can returnspecific test parameters (for example the specific time the vaneassembly (111) took to return to the vertical position) for evaluationby the user. Such indicator (811) will preferably be co-located with thecontroller to provide for immediate feedback.

Regardless of the types of systems used to initiate the testingprocedure, the testing procedure generally is performed in the mannerdiscussed above so as to provide for the various types of test anddetermine the respective outcomes. The systems and method of thedepicted embodiments, while effective for testing, can also provide foradditional benefits during testing over alternative methods.Specifically, the self-test system (101) will generally “fail safe” inthe event of a power outage or other interruption of the testingprocedure (such as loss of signal from the controller).

Because of the inclusion of the one way gate (203), the arm (201) willgenerally be unable to stop in a position where it inhibits the vaneassembly (111) from moving to an alarm condition in the event that thepaddle (115) is moved by a flow within the pipe. Thus, should a flowcommence while the self-test system (101) is in a disabled state, theflow detector (100) will generally still be operable. As can be seen inthe various FIGS. 3-7, regardless of the resultant position at which thearm (201) was to fail and “stick,” the vane assembly (111) will alwaysbe able to move to the alarm position and is not blocked by the arm(201). In the event that the arm (201) was to fail prior to the gate (asin FIG. 4), the vane assembly (111) can freely move without contactingthe arm at all (201). Should the arm (201) fail in front of the gate(203) (e.g. as in the position of FIG. 7), the vane assembly (111) canstill move as the gate (203) will move in the one way direction allowingthe vane assembly (111) to move past the arm (201). If the arm (201)should fail during testing (e.g., between FIGS. 4 and 5) while the arm(201) may slightly alter the force required to move the paddle (113)sufficiently to trigger the switch (205) in some embodiments, anactivation flow would generally still trigger the alarm. In this way, afailure at any time (except during the literal alarm switch test whereit would fail with the alarm activated) will allow the flow detector(100) to still turn on if flow commenced.

While the invention has been disclosed in conjunction with a descriptionof certain embodiments, including those that are currently believed tobe the preferred embodiments, the detailed description is intended to beillustrative and should not be understood to limit the scope of thepresent disclosure. As would be understood by one of ordinary skill inthe art, embodiments other than those described in detail herein areencompassed by the present invention. Modifications and variations ofthe described embodiments may be made without departing from the spiritand scope of the invention.

1. A self-test system for a paddle-type flow detector, the systemcomprising: an arm, the arm being used to displace a trip stem from afirst position to a second position wherein said trip stem is biased tosaid first position and said flow detector indicates flow when said tripstem is in said second position; a first sensor, the first sensordetecting when said trip stem is in said first position; a secondsensor, the second sensor detecting when said trip stem is in saidsecond position; wherein, when said trip stem is in said secondposition, said arm releases said trip stem and said trip stem returns tosaid first position because of said biasing; wherein, said self-testsystem determines the amount of time between when said first sensorstops detecting said trip stem and said second sensor detects said tripstem after said arm releases said trip stem; and wherein based on saidamount of time, said self-test system determines if a paddle is attachedto said trip stem.
 2. The system of claim 1 wherein said arm rotatesabout an axis.
 3. The system of claim 2 wherein said arm is sized andshaped to release said trip stem suddenly.
 4. The system of claim 3wherein said arm is generally teardrop-shaped.
 5. The system of claim 2wherein said arm rotates about said axis a first direction when said armis displacing said trip stem and a second direction after it hasreleased said trip stem.
 6. The system of claim 5 further comprising aone-way gate, said one-way gate being attached to said trip stem suchthat said one-way gate is rigid when said arm moving in said firstdirection contacts said one-way gate, but opens when said one-way gateis contacted by said arm moving in said second direction.
 7. The systemof claim 1 further comprising a one-way gate attached to said trip stem.8. The system of claim 1 wherein said first sensor and said secondsensor each comprise switches; wherein said first switch is closed whensaid trip stem is in said first position; and wherein said second switchis closed when said trip stem is in said second position.
 9. Apaddle-type flow detector including an auto-test system, the detectorcomprising: a housing; a vane assembly extending from said housing; abiasing mechanism biasing said vane assembly to a first position; afirst sensor which detects when said vane assembly is in said firstposition; a second sensor which detects when said vane assembly is in asecond position; an arm within said housing, said arm displacing saidvane assembly from a first position to a second position when anauto-test is initiated; wherein, when said vane assembly is in saidsecond position, said arm releases said vane assembly and said vaneassembly returns to said first position because of said biasing;wherein, said detector determines the amount of time between when saidfirst sensor stops detecting said vane assembly and said second sensordetects said vane assembly after said arm releases said vane assembly;and wherein based on said amount of time, said detector determines ifsaid vane assembly comprises a paddle.
 10. The detector of claim 9wherein said paddle-type flow detector is position in a fire sprinklersystem.
 11. The detector of claim 10 wherein said fire sprinkler systemis a wet pipe system.
 12. The detector of claim 9 wherein said armrotates about an axis.
 13. The detector of claim 12 wherein said arm issized and shaped to release said vane assembly suddenly.
 14. Thedetector of claim 12 wherein said arm rotates about said axis a firstdirection when said arm is displacing said vane assembly and a seconddirection after it has released said vane.
 15. The detector of claim 14further comprising a one-way gate, said one-way gate being attached tosaid vane assembly such that said one-way gate is rigid when said armmoving in said first direction contacts said one-way gate, but openswhen said one-way gate is contacted by said arm moving in said seconddirection.
 16. The detector of claim 9 wherein said vane assemblyincludes a trip stem.
 17. The detector of claim 16 further comprising aone-way gate attached to said trip stem.
 18. The detector of claim 9further comprising a key box, said key box allowing a user to initiatethe self-test.
 19. The detector of claim 18 wherein said key box furtherincludes an indicator indicating the result of said self-test.
 20. Thedetector of claim 9 wherein said first sensor and said second sensoreach comprise switches; wherein said first switch is closed when saidvane assembly is in said first position; and wherein said second switchis closed when said vane assembly is in said second position.